Polymeric compounds from 1,3-dioxolane



Patented Feb. 22, 1949 POLYMERIC COMPOUNDS FROM 1,3 -DIOXOLANE William F. Gresham, Wilmington, DcL, assignor to E. I. du Pont de Nemonrs as Company, Wilmlngton, Dcl., a corporation of Delaware No Drawing. Application February 21, 1945, Serial No. 579,148

10 Claims. 1

This invention relates to a process for the preparation of organic compounds and more particularLv to their preparation from 1,3-dioxo1ane and aromatic hydrocarbons. It likewise relates to the resulting polymers. This application is in part a continuation of application S. N. 424,296, filed December 24, 1941, now abandoned.

An object of the present invention is to provide new reaction products obtainable from the reaction of 1,3-dioxolane with other organic compounds. Another object of the invention is to provide new compositions of matter from 1,3-dioxolane or its substitution products and aromatic hydrocarbons or hyrocarbon substitution hydrocarbons. Another object is to provide reaction conditions and catalysts for such reactions, whereby valuable products are obtainable. Other objects and advantages of the invention will hereinafter appear.

Valuable products are obtained in accord with the invention by reacting 1,3-dioxolane, substituted 1,3-dioxolane, or reactants which form these compounds with the aromatic hydrocarbons, such as:

Benzene,

Toluene,

Xylene,

Ethyl benzene, Phenylethane, Mesitylene,

Methyl ethyl benzene, Propyl benzene, Cumene,

Durene.

Pentamethyl benzene, and

Hexam'ethyl benzene,

long chain alkyl benzenes, such as:

Amyl benzene, Octyl benzene, f Dodecyl benzene,

and especially those containing an alkyl group having more than 4 carbon atoms in the side chain.

The products of the invention are of relatively high molecular weight and will hereinafter be referred to as polymers, which term will include all products containing 1,3-dioxolane (or substituted 1,3-dioxolane) residues and aromatic hydrocarbon residues, there being present at least 2 three residues, two of which are similar.. For example, the polmers resulting from the reaction of 1,3-dioxolane with benzene will contain at least two 1,3-dioxolane residues and at least one phenyl residue, CcHcor vice versa.

The aromatic hydrocarbons maybe reacted in accord with the procedural details more fully particularized hereinafter, with 1,3-dioxolane and its substitution products. 1,3-dioxolane has the chemical formula with numbering as shown:

4 a 011,-0 l (23H:

H:O/ 5 1 and may be obtained by reacting formaldehyde or a formal with ethylene glycol. Products with substituents in the 2 position can be readily obtained by reaction of ketones or other aldehydes either aliphatic or aromatic with ethylene glycol. Thus, by way of example, many compounds are obtained which ma be employed in accord with the invention, such as 2-methyl-l,3-dioxolane, 2-ethyl-l,3-dioxolane, 2,2-dimethyl-1,3-dioxolane, 2,2-diethy1-L3-dioxolane, 2-phenyl-1,3-dioxolane, 2,2-methylphenyl-1,3-dioxolane,

4-ethyl- 1,3-dioxolane, 4-propyl-1,3-dioxolane, 4,5-dimethyl-1,3-dioxolane.

In lieu of 1,3-dioxolane, reactants may be used acid catalysts of this general nature.

which form- 1,3-dioxolane and in such reactions rivatives with large amounts of the aromatic compound, that is, in the order of 1-100 and the reverse is' also true. The greater the amount of 1,3-dioxolane present, the greater becomes the viscosity of the polymers until solids are eventually produced, while contrariwise, the: greater the ratio of the aromatic compound the less viscous will be the resulting polymer. .There appears to be no limiting factor restricting the proportion of reactants.

The reaction between 1,3-dioxolane and th aromatic compound is effected at temperatures ranging between 80 and 300 and preferably between and 150 C. Atmospheric subor super-atmospheric pressures may be used-and. if the last, pressure may range between 1 and 1000 atmospheres or higher. Normally excellent results are obtained at or about atmospheric pressure. If desired. the temperature of the reaction, especially when polymerization is carried out at the boiling point of the reaction mixture, may be controlled by varying the pressure on the boiling reactants.

It has been found advantageous to effect the reaction in the presence of an acid catalyst, such, for example, as sulfuric acid, phosphoric acid; the halogen acids, such as hydrochloric acid, hydrofluoric acid (alone or with BFs); boron fluoride (including its complexes with water, acids, esters, alcohols, and the like), paratoluene sulfonic acid, camphor sulfonic acid, and other Friedel- Crafts type catalysts other than BF: may be used, such as AlCls, AlBrs, FeCls, and so forth, as well as inorganic acids generally and their salts such as sodium acid sulfate, sodium acid phosphate, and so forth.

The catalyst maybe supported or not on inert supports such as charcoal, silica gel (which alone so forth. Concentrations of BF3,- H2804 and similarly strong catalysts may be extremely low; less than 0.1%, and amounts down to as low as 0.001% of the strong acid catalyst have been found sufiicient to give polymers although high concentrations of the catalyst even equal to or greater than the weight of the dioxolane are likewise satisfactory.

The reaction is preferably continued approximately to equilibrium in order to obtain the above defined polymeric organic compounds. The reaction may then be stopped by destroying the catalyst. This may be done by removing it (in the case of silicagel, kieselguhr, and the like) or by treating the reaction mixture with an inorganic base, such as ammonia, alkali metal, and alkaline earth metal hydroxides, carbonates, alkoxides, and so forth or an organic is a catalyst for the reaction), kieselguhr, and

base, such as pyridine, dimethylamine, and the merized product which remains treated for the recovery of the polymers.

In the reaction of the dioxolanes with the arcmatic compounds and more especially when the higher molecular weight products are being prepared there usually will be found in the reaction mixture along with the polymer unreacted dioxolane andthe aromatic compound together with by-products and polymers which it is not. desired to produce. It is possible to inhibit the formation of the undesired products by carrying out the process in an intermittent or continuous manner whereby the desired polymer is withdrawn from the reaction zone and the undesirable products, after being separated therefrom, are returned to the reaction zone. By this means it is possible to obtain high yields of the desired polymer.

In addition to being instrumental in stopping the reaction at the desired point, the neutralization of the catalyst tends to stabilize thepolymers. It follows, therefore, that for'high temperature uses no acid should be present in the polymers. They should preferably'be neutral or on the alkaline side.

Examples will now be given illustrating embodiments of the invention but it will be understood that it will not be limited by the details thereof. Parts are by weight unless otherwise indicated.

Example 1.A reaction mixture containing 736 parts of toluene, 148 parts of 1,3-dioxolane, and 8 parts of boron fluoride was heated on a steam bath under a returned condenser supplied with a calcium chloride drying tube for 5 hours. In the initial stage of processing boiling occurred. As reaction progressed a colorless viscous liquid was produced. The cooled reaction product was treated with a stream of anhydrous ammonia (until blue to litmus) followed by 3.1 parts of sodium hydroxide dissolved in 10 parts of water. Unconverted 1,3-dioxolane and water were removed under reduced pressure, the last traces at C. and 1 mm. pressure. The product, 51 parts, was a practically colorless viscous liquid boiling higher than 74 C. at 1 mm., and was only partially soluble in water.

Example 2.-Under conditions described in Example 1, 20.4 parts of a long-chain alkyl benzene (prepared from benzene and a mixture of olefines which boiled at -140 C., which in turn was prepared by dehydrating a mixture of alcohols boiling between and 0., ob-

tained by the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, by passing the mixture of alcohols over an aluminum phosphate catalyst at a temperature of approximately 400 0.), 222 parts of 1,3-dioxolane and 2.4 parts of boron fluoride gave 163.5 parts of a light brown viscous liquid having the following physical and chemical constants: hydroxyl No. 69, molecular weight 1820.

The modified aromatic organic compounds of the invention are adaptable for use as organic intermediates and for use as solvents-and plasticizers for films and filaments of cellulose derivative's and polyamides generally.

The polymers hereinbefore described may be used as plasticizers for rubber, artificial rubber, and resins generally; as sizes, softeners, mercerizing assistants, crushproofing assistants and assistants in textile uses; the high molecular weight polymers may find utility as films for use as greaseprooi' liners for food containers, bulletproof gasoline tanks and so forth; as polishes and waxes, and especially as substitutes for the mineral and vegetable waxes such as parafiin, ceresin, carnauba, japan, montan waxes and so forth; as print compositions, duplicator pad ingredients, paper sizes, paper adhesives, greaseproofing agents, and protective coatings gener ally; as electrical insulators; as dispersing agents for rubber and latex; as ingredients in copolymers with rubber, artificial rubber, resins, and plastics, as protective coatingsifor rubber and, ingredients in self-sealing tires and tubes; as leather preservatives, softeners, plasticizers, and agents to make leather fat resistant; as dispersing agents and binders for cosmetic creams, lotions, lipstick and so forth; as sealing agents for oil and gas wells; as drilling mud ingredients control thixotropy; as settling, viscosity, and flotation agents in ore treating; as binding agents for finely divided materials, such as ceramic pigments and so forth; as agents to prevent curling in cellulose films; as binders for abrasive wheels; as cutting aids in metal turnng; and as plasticizers for glue, casein, proteins, gelatin, cork, cellulose and cellulose derivatives.

I claim:

1. A process of making liquid polymers con- .aining benzene and 1,3-dioxolane residues, there )eing present at least three such residues in the iolymer which comprises mixing 1,3-dioxolane vith benzene and efiecting the polymerization in he presence of a boron trifluoride catalyst at a emperature between 50 and 150 C.

2. A process of making liquid polymers conaining an alkyl benzene and 1,3-dioxolane resi- Eues, there being present at least three resiues in the polymer which comprises mixing ,3-dioxolane with an alkyl benzene and effecting he polymerization in the presence of a boron rifiuoride catalyst at a temperature between 0 and 150 C.

3. A process of making liquid polymers of 1,3- ioxolane and long chain alkyl benzenes obained from benzene and a mixture of olefines oiling between 120 and 140 0., obtained by deydratlng a mixture of alcohols, resulting from he catalytic hydrogenation of carbon oxides nder elevated temperatures and pressures, hich boil between 170 and 190 C., which comrises subjecting a molar excess of 1, 3-dioxolane 'ith such long chain alkyl benzenes to polyierization in the presence of a boron trifluoride atalyst and at a temperature between 50 and 50 C.

4. A process of making liquid polymers of 1,3- dioxolane and toluene which comprises heating a reaction mixture containing about 736 parts of toluene, 148 part-s of 1,3-dioxolane and 8 parts of boron trifluoride on a steam bath under a reflux condenser for about 5 hours, treating the cooled reaction mixture with anhydrous ammonia until blue to litmus, adding about 3.1 parts of sodium hydroxide dissolved in 10 parts of water and, thereafter, removing the unconverted 1,3-dioxolane by distillation.

5. In a process of making liquid polymeric products from 1,3-dioxolane, the step which comprises mixing 1,3-dioxolane with an aromatic compound of the group consisting of benzene and alkyl benzenes and effecting the polymerization by heating to a temperature between and 150 C. in the presence of a boron trifluoride catalyst, thereafter neutralizing the catalyst and recovering the polymeric product.

6. The process of claim 4 in which the aromatic compoun'd is toluene.

7. In a process of making liquid polymeric products from 1,3-dioxolane, the step which comprises mixing a molecular excess of 1,3-dioxolane with a compound of the group consisting of benzene and alkyl benzenes and causing a polymer to be formed between these reactants by contacting the mixture with a boron trifluoride catalyst at a temperature between 50 and 150 C., thereafter neutralizing the catalyst and recovering the polymer.

8. A liquid polymeric condensation product of 1,3-dioxolane and an aromatic compound of the group consisting of benzene and alkyl benzenes.

9. A liquid polymeric condensation product of 1,3-dioxolane and toluene.

10. A liquid polymeric condensation product of 1,3-dioxolane and long-chain alkyl benzenes.

WILLIAM F. GRESHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I Name Date 2,098,108 Reppe Nov. 2, 1937 2,187,081 Hodgins Jan. 16, 1940 2,366,737 Loder Jan. 9, 1945 2,394,862 Loder et al Feb. 12, 1946 

